Lifting-jack.



P. E. PARNHAM.'

LIFTING JACK. y APPLIOATION FILED MAY 12, 1908.

Patented sept. 22, 1908."

lriuso n. immuni, oi iiU'uronD FALLS, .n.ux. i

LIFTING-JACK.

Specification c-f Letters' Patent.

Y appiicacion ined May 1,2, 190s. seriai No. 432,423.

Patented septse 1908.

25 tangular cavity in each end of said case is a cani faceI 32 and is piovided for engagement 80 plunger, 7 at the top and S at the lsottom. with pin 37 fixed in frame portion 3. The As said plungers are alike in all particulars I' engagement of said pin 37 with groove 35 will describe in detail only ene. Plunqer 7 retains cani face 32 in constant contactwith is provided with side plates 9, 10 held therethe cani face of cam 250 therebelow and 30 to by screws as 11. Said plates extend maintains gear teeth 330 constantly in mesh 85 downwardly for carrying roller bearings 12, with the screw-threads of shaft 15. Groove 13 respectively in which are supported the. 36 is engaged by pin ixediiithe lowerporoutboard ends of cam roll 14. Plates 9, 10 tion of )late 9 ol' plunger 7. Said groove 36 Y have holes 16, 17A respectively therethrough Vis parallel with face 34 of cam 25 and the 35 for inspection and oiliiig of the bearings. engagement of said groove with pin 3S main- 90.

The principal thrust of said roller bearings tains face 34 in constant conta-ct with cam 12, 13 is taken by seats 18, 19 formed diroll 14. rectly iii plunger 7. Cain roll 14 is shoul- Plungei's 7, Smaybe provided with adiustdeied down at its ends for engagement with able heads as head 39 of plunger 7 Adjustli the roller bearings whereby the rolls of said ment of said head 39 relative to plunger 7-is 95 hearings are prevented from working inhad by means of screw threads 40 on the wardly on their seats. Y shank of said plunger in engagement with Located horizontally, 'afi'iglit angles to complementary screw threads in plunger 7. cam roll 14, in suitable bearings 20, 21 and The operation of in v improved jack is as 25 midway vertically and crosswise in case 3, 4, follows: Upon turning shaft 15 in a clock- 100 is screw shaft 15. Said sha-ft is provided wise direction (Fig. 2) cam 25 is caused t0 with collars as 22, 23 for engagement with its turn in an anti-clockwise direction and cam hearings in ease 3, -1 to prevent endwise 250 to tui-n in a clockwise direction (Fig. 1).` movement of said shaft.. Also said shaft 15 This causes the coacting faces of said cains o has at least one end squared as at 24 or otherto roll together and axis 27 of cani 25 to rise 10`5 To all I:157mmit muy concern.'

le it known that l, Flinn E. Faiixiian, a citizen of the tinted States, and resident of ltuinfoid Falls, in the county of O xford alid taken on line 2, 2 of Fig. l.

The containing caseof my device is preferably made in two symmetrical halves 3, 4

held together by 1nolts 5, 6 ete. In a ieewise fashioned for the. engagement of a crank or wrench.

Above shaft 15 and between it and cani roll 14 is cam 25, of peculiar construction.

' most inl Fig. 1

140 is cani 250 similar in all particulars to cam 25 and engaging therewith. A description of cam 25 will siitlice. for both it and cam 250. lCani 25 is provided with axial shaft 27 desired said face 34 may also be cam shaped;

, 5 State of Maine, have invented certa-iii new fixed therein and on each end of said shaft is 60 t and useful Improvemeiitsin Lifting-Jacks, of a sleeve as 28. Said sleeves and the shaft which the following is a specification. ends therein may move i-ipwaidly from the This invention relates to lifting jacks and position shown, in slots as 29 in case 3, 4 and directly to that class thereof which aie cani said sleeves are retained on their respect ive actuated. shaft ends by plates as 30. Said plates are 65 i i In the drawing accompanying this speciheld to case 3, 4 by screws as 3l, 3i. Said g cation is illustrated one embodiment., and cam 25 has its cani face 32 preferably uniwhich may he the preferred embodiment, of forinly increasing iipwai'dlyin dista-nce from i in v improvements. axial shaft 27 and said face has a. central l 'lheren Figure 1 is a front elevation of my groove 33 therein parallel with said face. 70 i. device. T heupper half of said Fig. 1 has the The bottom of said groove is provided with g front portion thereof removed to hetter show teeth 330 for engagement with the threaded details of the mechanism. Fig. 2 is a side oiftion 150 of screw 15. Face 34 of cam 25 elevation, partly in section, and correspondying axially opposite to cam face 32 is prefv 2o ing` with Figv 1. The section of said Fig. 2 is erahly formed concentric with axis 27 but if 75 The sides of cam are each provided with grooves as 35 36 in that face lviiig u a er- 2:, i F

Groove 3o is parallel with tion is imparted to plunger `S by cani 250.

By reversing the direction of rotation of screw 15cams 25, 250 are caused to reverse their directions of rotation and by means of the engagement; of pins and grooves, as pin 37 in 5 groove 35, cam 25 is drawn downwardly and by means of the engage-nient of pins and grooves as pin 38 in groove 36 plunger T is returned to its lower position (Fig. 1). The

saine operation is carried vout in refe-rence to i0 cam 250 and plunger S but in the opposite direction.

B 'v in v improved construction plunge `s 7,

' S can be moved only by the rota-tion of shaft: and said rota-tion. may be stopped at any l5 pointv without danger of'phingers 7, slipping back or ruiming down. Said plungeis Vare always locked against movement a: any point in their upwaidor downward move-- ment without. any special device therefor, sueh as ratchet and pawl.

I claim:

1. The combination of a cam member hav ing teeth -in the cam face thereof, a screw member for en.;a :ementI with the teeth of the cam member, means for maintaining those teeth in engagement willi the screw member atfa const ant dista-nce from the axis of the screw member and mea-ns for rotating the screw member.

2. The combination of a rotatable men'- ber, a'portion of whose periphery is a cam,

-teeth formed in the cani face, tliatporion of the 'periphery axially opposite said cam face being concentric with the axis of said rotatable member., a toothed member for engagement with the teeth in the rotatable member, a slidable member for ciigagenitnt. with the. concentric face. of the rota-table member, means for guiding the axis ot the rotatable 40 member in the line of .travel of the slidable member and means for rota-'Sing the toothed member.

3. The combination of a rotatableinembei', a portion ot' whose peripheryy is a cam,

teeth formed in the cam face, that portion of the periphery axially o iposite said cani face being concentric with the axis of said 'rotatable member, a toothed member for engagementA with the teeth in the rotatable niember, a slidable member for engagement with the concentric face of the rotatable member, means for maintaining a constan't reiation between those teeth of the rotatable memberv in engagement with the toothed member and the toothed member and means for maintaining a constant relation between the slidable member and the axis of the rotatable member, means for guiding the axis of the rotatable member in lthe line of travel of the 30 slidable. member and means for rotating the toothed member.

4. ri`he combination of a pair of oppositely disposed coacting cams, a peripheral groove in each cam face, teeth in said grooves, a

screw member in common engagement with sealer i the teeth of both cams and a plunger act-uated by each cam, and means for rotating the screw member. y g

5. The combination of a pan' of oppositcly disposed enacting cams, a peripheral groove in each cani face, 4teeth in said'grooves, a screw member in common engagement with the teeth of both cams and a plunger actuated by each cam, means for maintaining each cam in coaction with the screw member, means for maintaining each plunger in coactioii with its respective cam, and means for rotating the screw member.

(i. The combination of a pair of oppositely disposed coacting cams, a peripheral groove in each cam face, tc'cth in said grooves, a screw member in common engagement with the teeth o both cams, a pair of plungz-rs each having an antilriction roll mounted therein for engagement with each of the c/anis respectively and meansfor rotating/ the screw member. V

7. The combination of a pair of oppositely disposed coacting cams, a peripheral groove l in each cam face, teeth in said grooves, a screw member in common engagement with the teeth of both cams, said camseach having a peripheral portion concentric with its axis of rotation, a slidahle member in en.

gagement with the concentric portion of each cam, means for guiding each cani axis in the line of movementof its slidable member and means for rotating the screw member.

S. The combination of a pair of o'ppositely" disposed coacting cams, a peripheral groove in each cam face, tceth'in said grooves, a screw member in common engagement with the teeth of both cams, said cams each having a peripheral port-ion concentric with its axis of rotatiom'a slidable member in cngagement with the concentric portion of eac-h cam, means for guiding each cani axis in the line of movement of its slidable meni-` ber, means for maintaining each cam in coaction with the screw member, means for ford Falls, A\Iaine before two subscribing witnesses.

FRED F. FARNIAU. YVi tnesses:

CHARLES E.l GARCELON, Fnxxic J. COLBY. 

